Air-heating furnace for alternative forced and convection air flows



Nov. 28, 1950 w. F. CRELL 2,532,089

AIR HEATING FURNACE FOR ALTERNATIVE FORCED AND CONVECTION AIR FLOWS Filed April 8, 1946 2 Sheets-Sheet l /6 imhnnnnnnnnn' a uuuuuuuuu (a w/LLY r- CRELL 3% QMM Nov. 28, 1950 2,532,089

W. F. CRELL AIR HEATING FURNACE FOR ALTERNATIVE FORCED AND CONVECTION AIR FLOWS Filed April 8, 1946 2 Sheets-Sheet 2 INVENTOR. WILL! F'- CRELL BY arr.

Patented Nov. 28, 1950 UNITED STATES 1 OFFICE AIR-'HEATING FURNACE .TFOB ALTERNATIVE FORCED CONVECTION AIR FLOWS Willy F. :Crell, Cleveland, Ohio Application April :8, 1946,?Se1ia111N0. 60,381

:3 Claims. 1

The present invention relates to -heaters, furnaces, and'the like, and is moreparticu'larly concerned with domestic heaters or furnaces especially constructed for the use of gas or oil as a fuel, but it is to be understood that the invention is not necessarily limited to any particular kind of fuel.

Heaters and furnacesefieot movement of the fluid to be heated by gravity in so-called gravity heating systems or '-by forced draft in so-called forced'draft heating systems, which systems are highly efficient only under favorable conditions and, therefore, both gravity and forced draft heaters and furnaces generally cannot operate at high efliciency.

The general object of the present invention is the provision of a heater or furnace which includes both a gravity heating systemand'a forced draft system, the systems "being coordinated for selective and individual movement of the fluid to be'heated by gravity'or forced'draft for selective individual use of either heating systemand'highest possible efficiency of the heater or furnace.

Such a general object of the invention is attained-by a furnace provided with botha gravity heating system and a forced draft heating systemywhich furnace includes a heating chamber adapted to communicate and form part of either the gravity heating system or the forced draf-t heating system, and which embodies means 'to selectivelyprevent communicationof the heating chamber with the gravi-ty'heating system or the forced draft heating system.

.Another object of the invention therefore is the provision of a furnace having passage ways for a gravity heating system and a forced draft heating system and including a single heating chamber adapted to be selectively brought into communication .with the passage ways of the gravity heating system or the forced draft heating system.

Gravity heating systems have in the heating chamber an upwardly directed flow of the fluid to be heated, therefore, heat absorption =by such fluid decreases when same "travels upwardly through the heating chamber away from the source of heating energy. Forced draft heating systems have in their heating chamber :a zflow of the fluid to be heated directed so as to .obtain best possible heat absorption by the fluid when travelling through such iheating chamber, that is, the direction of travel of such fluid in the heating chamber is generally toward the source of heat energy, that is, downwardly, as the A 2 source of heat is located at the bo'ttom portion of a furnace.

further object of the invention, therefore, is theprovision of a furnace having passageways for a gravity heating system and a forced dr-aft heating system, a single heating chamber and means to selectively bring the heating chamber in ---communication with the passage ways of the gravity heating-system'or the forceddraft heating system, so that the fluid to be heated travels in said heating chamber in an'upward direction when such chamber communicates with the passage ways of the gravity heating system, and travels in said heating chamber in a downward direction when such-chamber communicates with the passage :ways of the forced draftheating system.

With the-above and'other incidental objects in view, the invention has other marked improvemerits and superiorities which radically distinguish it from presentlyknown structures. These improvements or superior characteristics embodying certain novel features 0f.COIlStll1GtiOn*3.i;8 clearly set forth in the appended-claims; and ;a preferred form of embodiment of the invention is hereinafter shown with reference to the accompanying drawings forming part of the speci- In "the drawings:

Fig.1 is a vertical sectionalview of a gas'heated furnace embodying the invention, the furnace including a gravity heating system, a forced draft heating-system,-and means for selectively operating either system and direct the flow of fluid through the heating chamber inthe direction 'bes't suited for the respective heating system.

-Fig.*2 is a-vertical-cross sectional view through the furnace shown in Fig. 1, the section being taken on line 22 of'Fig. 1.

Fig. 3 is -"a side-view, partly in section, of the furnace-shown in Fig. 1, the section being taken on line -3--3 of Fig. "1.

Fig.4 is-a front-view of the furnace shown in Fig. 1, showing the operating means for selectively coupling the heating chamber with the gravity heating system or the forced draft heating system.

Referring now more particularly to the structure-shown in the drawings, the furnace disclosed therein embodies a casing 2 of substantially rectangular cross section closed at its top 3 and supportedon abase d, preferably cemented-thereto. This casing is subdivided by a vertical wall 5 into a heating chamber 6 and a passage way 1 in valve-controlled communication with each other through openings 8 and 9 in the top and bottom portions of vertical wall 5. Heatin chamber 6 supports in its lower part a combustion chamber II! which has disposed therein a gas burner I I provided with the usual outlet openings [2 for combustible gas. This burner, which is supplied with gas from any suitable source and controlled in any suitable manner, extends substantially the entire length of the combustion chamber which is open at its front end and outwardly extended of casing 2 to provide the chamber with sufficient combustion supporting air. Combustion chamber ll] communicates through a plurality of separate individual zigzag-shaped pipes [4 within chamber 6 with a header also within said chamber, which header is extended outside of easing 2 for leading combusted gas to a flue or chimney. A plurality of baffle plate members 16, preferably arranged opposite the coil portions ll of pipes l4, provides a circuitous path for fluid travelling through chamber 6, as will be later described.

Heating chamber 6, in addition to openings 8 and 9 in wall 5, has in its wall i8 opposite wall 5 and its openings 8 and 9 other valve-controlled openings l9 and to form said heating chamber with opposed upper and lower valve-controlled inlet and outlet openings, as will be described hereinafter. Openings l9 and 20 are the inlet openings for chamber 8 and openings 8 and 9 the outlet openings for said chamber. Upper inlet opening l9 effects Valve-controlled communication of chamber 6 with an air compressor 2i communicating with the cold air return pipe 22 which also communicates with the open air through a valve-controlled branch pipe 23 and is extended at its lower end portion 24 into lower inlet opening 29 of chamber 6 (see Fig. 1).

The inlet and outlet openings I9, 20 and 8, 9 are controlled by valve members 25, 26 and 21, 28 respectively, pivotally supported by the respective walls I8 and 5. These valves, when shifted to their one position, are set for forced draft operation of the furnace, in which operation air is drawn through cold air return pipe 22, forced through upper intake opening is in wall l8 into heating chamber 6, hence forced in heat exchange with pipes it downwardly through the circuitous path in said chamber to and through lower outlet opening 9 and, finally, upwardly through passageway 1, outlet 29 and pipe 30 into the rooms to be heated, all as indicated by full line arrows in Fig. 1 of the drawings. The valves 19, 2B and 8, 9, when shifted to their other position by means of a mechanism 3! including a handle 32 actuating a chain 33 engaging chain pulleys 34 at the ends of the pivot shafts of said valves, are set for gravity operation of the furnace. In such an operation air enters through cold air return pipe 22, its lower end portion 29 and lower intake opening 29 in wall I8 into heating chamber 6 and travels in heat exchange with pipes l4 upwardly through the circuitous path in said chamber to and through upper outlet opening 8 and pipe 39 into the rooms to be heated, all as indicated by dash-dotted line arrows in Fig. 1 of the drawings.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of the invention, and it is therefore not the purpose to limit the patent granted thereon otherwise than necessitated by the scope of the appended claims.

Having thus described my invention, what I claim is:

1. In a furnace, selectively actuated, associated gravity and forced draft air heating systems, said systems including means defining a heating chamber common to both systems, means defining inlet and outlet passages in both the upper and lower portions of said heating chamber, valve means for each of said inlet and outlet passage means, controlling means for said valve means, an air intake passage with branches communicating with the said air inlet passages, and a blower in the branch communicating with the inlet passage in the upper portion of the heating chamber, said controlling means in one position effecting closing of valve means for the inlet passage in the upper portion of the heating chamber and the outlet passag in the lower portion thereof and opening of the valve means for the remaining other passages of such heating chamber to effect operation of the gravity heating system having the air to be heated traveling upwardly in the heating chamber, and said controlling means in another position effecting closing of the valve means for the outlet passage in the upper portion of the heating chamber and the inlet passage in the lower portion thereof and opening of the valve means for the remaining passages to effect operation of the forced draft heating system, forcing by said blower in the said one branch of the air intake passage air to be heated into and through the inlet passage in the top portion of the heating chamber and downward travel of such air in th heating chamber.

2. A furnace as described in claim 1 including means defining a combustion chamber in the lower portion of said heating chamber, a plurality of flue pipes extending from said combustion chamber upwardly in said heating chamher, and a header arranged in the upper portion of said heating chamber and connected to said flue pipes and extended outside of said heating chamber.

3. A furnace as described in claim 1 including means defining a combustion chamber in the lower portion of said heating chamber, a plurality of individual zig-zag shaped flue pipes extending from said combustion chamber upwardly in said heating chamber, a header arranged in the upper portion of said heating chamber and connected to said flue pipes and extended outside of said heating chamber, and a plurality of baflle plate members arranged opposite to th curved portions of said flue pipes to provide a circuitous path for air travelling through said heating chamber.

WILLY F. CRELL.

REFERENCES CITED The following references are of record in the file of this patent: 

